A novel dendritic europium complex containing grafted carbazole units as functional peripheries was synthesized and characterized. The Foerster energy transfer from the peripheries of carbazole units to β-diketonate as well as from the hgands to the central Eu(Ⅲ) ions in the complex was demonstrated. Under the excitation of carbazole units and β-diketonate, characteristic red emission peaks at 612 nm with four shoulders due to the Eu(Ⅲ) ion transition of 5^D0→7^FJ (J=0-4) were observed for the complex.
A novel heterometallic complex [Na2Cu2Gd2(pdc)4(H2O)14·2H2O] (H3pdc = 1H- pyrazole-3,5-dicarboxylic acid) has been synthesized and characterized by 1R spectra, elemental analysis, and single-crystal X-ray analysis. The crystal belongs to the monoclinic system, space group P2 1/c with a = 7.9521(18), b = 12.251(3), c = 22.293(5) A, β = 110.173(5)°, V= 2038.5(8) A^3, Mr = 1388.13, Z = 2, F(000) = 1352, Dc = 2.261 g/cm^3,/2 = 4.380 mm^-1, the final R = 0.0409 and wR = 0.0622 for 2453 observed reflections with I 〉 2σ(I). The structural analysis shows that the Na^I, Cu^II and Gd^II ions are linked together by two kinds of bridging ligands (pdc^3- and H2O) to form a main moiety [Na2Cu2Gd2(pdc)4(H2O)14], which can be regarded as a centrosymmetric dimmer of [NaCuGd(pdc)2(H2O)7]. Many hydrogen bonds exist in the complex to build a 3D supramolecular framework.
Two novel interpenetrated coordination polymers,[Zn(IBA)2]n (1) and {[Cd(IBA)2(H2O)].4H2O}n (2),have been synthesized by using 4-imidazole-benzoic acid (HIBA) as ligand under hydrothermal con-ditions. Complex 1 crystallizes in a chiral space group and has a two-fold interpenetrated 2D network structure with (4,4) topology,while complex 2 is a 3D porous dia network with four nets interpene-trating each other. The SHG activity of 1 and the photoluminescent property of 2 have been investi-gated.
BAI ZhengShuai,CHEN ShuiSheng,ZHANG ZhengHua,CHEN ManSheng,LIU GuangXiang & SUN WeiYin State Key Laboratory of Coordination Chemistry,Institute of Coordination Chemistry,School of Chemistry and Chemical Engineering,Nanjing University,Nanjing 210093,China
Unprecedented synthesis of chiral (aza)crown ethers of calix[4]arene derivatives bearing a carboxyl amide bridge was described. The synthesis proceeds through condensation of the corresponding dinitriles with optically active 1,2-aminoalcohols, and is catalyzed by the ZnCl2 Lewis acid at elevated temperature in a very efficient one-pot process. The cavity of calix[4](aza)crowns can encapsulate methanol molecules by O-H⋯п interaction, which has been confirmed by X-ray crystal structures and ESI-MS.
ZhengYi Li MingYu Teng JieJie Ma Ji Huang LeYong WangYi Pan
Three complexes obtained by the reaction of Pr(Ⅲ) or Nd(Ⅲ) salts with 5-methyl-2-pyrazinecarboxylic acid(Hmpca) are structurally determined by single-crystal X-ray diffraction.Complex [Pr(mpca-)3(H2O)2]2·6H2O(1) is composed of dinuclear Pr(Ⅲ) units with two metal centers bridged by two anionic mpca-ligands in a κ^3O,O':O' bridging mode.Complexes [Pr(mpca-)3]n(2) and [Nd(mpca-)3]n(3) are isostructures,and they consist of polymeric chains based on Ln(Ⅲ) and mpca-ligands.Each pair of adjacent metal centers is linked by three mpca-molecules in a κ^3N,O:O bridging mode.
Three tripod molecules, tris(2-methoxy-5-nitrobenzyl)phosphine oxide (1), tris(2-butoxy-3-methyl-5-nitrobenzyl)phosphine oxide (2), and tris(3-nitrobenzyl)amine (TNBA), were synthesized and crystallized. The structures of 1, 2, and their comparison (TNBA) were determined by X-ray crystallography. It is noteworthy that compound 1 interacted with adjacent molecules via π-π stacking and C-H···π interactions to yield an open supramolecular network with the porosity P in 8.9%, whereas compound 2 gathered closely to form an open-dimer capsule by sixfold N-O···π and triple C-H···O interactions, which showed a rare example of a stable in, out-invertomer of phosphine inversion existing in open-dimers. A series of columns were built and arranged side by side by these weak interactions. By contrast, TNBA crystallized to form a 2D network maintained by C-H···O and C-H···πinteractions. It seems minor changes of the chemical structure may cause large differences in the crystal structure and interactions in crystal engineering.
HAN Jun1, DENG Chao1, FANG Ru1, LI YiZhi2, WANG LeYong1& PAN Yi2 1Key Laboratory of Mesoscopic Chemistry, Ministry of Education
A series of new fluoro-containing copolymers have been synthesized by a Mitsunobu reaction with 4,4'-(hexafluoroisopropylidene) bisphenol A(6FBPA) and the corresponding N,N-dihydroxyethylaminoaryl azo or ring-locked triene compounds, which have high thermal stability and good solubility in organic solvents.The nonlinear optical(NLO) measurements made by Marker fringe method at 1064 nm indicate that the copolymers embedded with the ring-locked triene and azo chromophores exhibit higher macroscopic nonlinear optical coefficient(70.2 pm/V and 26.5-34.6 pm/V,respectively).Thermal analysis and UV-visible absorption spectra show that the copolymers have good thermal stability(T_d= 264-319℃) and optical transparency (λ_(max)500 nm).
Jie Ping Shi Hui Yang Li Wei Hong Wen Hu Guo Yuan Lu